Prior to the abort of Apollo 13, Apollo 14 was targeted to land in the Littrow region of Mare Serenitatis, where the objective was to study young, pyroclastic volcanic deposits. Following the Apollo 13 abort, it was decided to retarget Apollo 14 to the Fra Mauro site, which was regarded as scientifically more important than the Littrow site. Also, landing in Fra Mauro would allow the astronauts to obtain orbital photography of the Descartes region, something that was not possible if Littrow was the landing site. Descartes was regarded as a high-priority target for a later mission (eventually flown by Apollo 16), but could not be certified as a safe landing site based on Lunar Orbiter photography. Although Littrow was rejected as the Apollo 14 landing site, another site in Mare Serenitatis, Taurus-Littrow, was later explored by Apollo 14.

Headshot

Apollo 14 (a H mission) was originally targeted for Littrow crater, not the Taurus-Littrow valley that Apollo 17 eventually visited. When 13 did not land, the powers that be decided that Fra Mauro was important enough to retarget 14.

Later in 1970, Apollos 15 and 19 were cancelled and the landing sites revised. The "old" Apollo 15 (also a H mission) was being considered for Hadley Rille, not the Hadley-Appenine site that the "new" 15 (now a J Mission) eventually landed. Apollo 16 always seemed destined for Descartes.

The real question was where to send 17. The final three candidate sites were: Taurus-Littrow (resurrected by orbital photography from Apollo 15), the Marius Hills complex, and a large crater, probably Copernicus (the scientists wanted Tycho but were told that would never happen).

Mostly likely the two remaining sites would have been visited by 18 and 19, had they not been cancelled. There were two viable sites within Copernicus, one near the central peak and another almost due north near the rim. It would have been very interesting to see which of the two would have been chosen.

Glint

When did the relatively northerly Schroeter's Valley/Cobra Head site fall off the list? I thought this site of reported TLP sightings remained in the running for one of the canceled missions.

The report recommends three possible landing sites in the area of Schroeter's Valley, which was the committee's #8 choice.

By the way, I notice that one of the members of that committee is a Harrison H. Schmitt. Another member is Farouk EI-Baz.

Headshot

That list was put together by scientists as a wish list, then it had to be examined and vetted by the mission ops people and flight engineers.

Schroter's Valley is too far North and was deemed to be inaccessible to Apollo by the operations people, even for the H missions. It also became moot when Hadley-Appenine was chosen for Apollo 15's landing site. The scientists would get a landing near a rille, but it would be Hadley's.

I do not believe that the TLP issue was even a factor in the decision process.

Fra Mauro

What was the appeal of Marius Hills, besides the relative safeness of the site?

Glint

quote:Originally posted by Headshot:Schroter's Valley is too far North and was deemed to be inaccessible to Apollo by the operations people, even for the H missions.

Apollo 15's Hadley Rille landing site was a full degree farther north than the Shroeter's Valley landing site near Aristarchus. Perhaps Longitude may have been another factor. No other Apollo landing site had a Longitude as far away from the lunar Meridian as the recommended Schroeter's Valley landing site (49.5W).

The location likely made high resolution photographic reconnaissance of the area by Apollo mapping missions leading up to a landing there problematic.

quote:It also became moot when Hadley-Appenine was chosen for Apollo 15's landing site. The scientists would get a landing near a rille, but it would be Hadley's.

The Aristarchus site at Schroeter's Valley not only had a rille, but also the "Cobra Head" feature. Would have been interesting to explore the "source" of the rille:

"Schroeter's Valley terminates on one end in what early selenographers were inspired to call the Cobra Head, a large deep depression which is interpreted as its source."

However, as you already mentioned above, the area had accessibility issues, being described as "rather rugged," and the Cobra Head itself, although "a very important feature, would be inaccessible."

quote:I do not believe that the TLP issue was even a factor in the decision process.

Perhaps not in the final decision process, but TLP definitely was a significant consideration in the panel's recommendation starting on the summary page where it makes reference to the Cobra Head's "transient phenomena" on p. vi. Also, the main write up on p. 40 states the Cobra Head "is characterized by its high thermal anomaly and the repeated occurrence of transient phenomena."

Glint

quote:Originally posted by Fra Mauro:What was the appeal of Marius Hills, besides the relative safeness of the site?

As a clarification to the landing accessibility issue. Longitude was indeed a critical factor. The landing "envelope" for H missions was only 7 degrees above or below the lunar equator at the longtitude of Schroter's Valley. Yet it was nearly plus or minus 40 degrees latitude near the longitude of Apollo 11's landing site.

There is a very nice diagram of Apollo landing site accessibility on page 63 of The International Atlas of Lunar Exploration.

As far as the lure of the Marius Hills landing site. Apparently the geologists, geo-chemists and geophysists had a real fixation on its complexity as they believed that there were volcanic cones in them thar hills.

Descartes was not mentioned at all in the early site possibilities. When did that one come up for consideration?

Copernicus would have been a cool landing site. There were plans to land inside the crater north of the central peak.

Headshot

That is an interesting list. Did the publication indicate who or what committee generated it?

The problem is that several groups were generating landing site lists. Bellcom, the Group for Lunar Exploration Planning (GLEP), the ASSB and at least one other. GLEP's 10 July 1969 list had Descartes listed for the J-5 (Apollo 20) mission. Tycho appeared on a number of lists, but finally George Low threw cold water on that site when he said that he would never allow an Apollo mission to be targeted for Tycho.

The only three sites that were constant on all lists that I have seen were: a "Red" Mare, a "Blue" Mare, and Fra Mauro.

Apollo 11 actually had multiple landing sites. If it launched on July 16, they would target Mare Tranquillitatis; if the launch slipped to July 18 - Sinus Medii; if it slipped further to July 20 - Oceanus Procellarum. Once 11 landed at the Mare Tranquillitatis, scientists had their old "blue" mare and 12 would be sent to a young "red (or slightly less blue)" mare as Don Wilhems called them. Had 11 landed in Oceanus Procellarum, 12 would have probably been sent to Mare Tranquillitatis and Conrad and Bean would have snipped pieces off of Surveyor 5.

Except for Fra Mauro, the rest of the landing site choices evolved as we: (1)learned more about the moon from samples returned by previous missions and (2) got back hi-res photography of other potential landing sites.

The other monkey in the wrench for these landing site lists is that in 1970, three Apollo missions were cancelled and 13 failed to land. So that year we lost four landing sites and the lists had to be pared down accordingly which, of course, made for some intense meetings.

The two best soruces on the subject (that I have found) are NASA's Where No Man Has Gone Before, which has some interesting tables of landing sites, and Don Wilhems' To A Rocky Moon, which details some of the discussions and maneuvering by scientists to get THEIR site chosen by Apollo Management.

Fra Mauro

Were all of the Apollo 11 sites similiar in terrain and features?

Headshot

Yes, they were all flat and "boring." The engineering and operations people chose the most featureless mare sites that could be determined from Lunar Orbiter photography. Remember, for Apollo 11, landing safely was the main goal and at that time we had no idea how close to the target point 11 would land. Scientifically interesting sites were reserved for subsequent missions.

Glint

quote:Originally posted by Glint:When did the relatively northerly Schroeter's Valley/Cobra Head site fall off the list?

Still looking for a definitive answer to my own question, found an online NASQ HQ history source with a table showing that as of June, 1969, Shroeter's Valley (i.e. Aristarchus) was still on the list.

Later, there's another table indicating that by the following month the Aristarchus site was not included in a list of 10 sites proposed for Apollos 11-20 by the Apollo Site Selection Board.

The evolution of the selection of Apollo landing sites is truly a fascinating subject.

Headshot

"The evolution of the selection of Apollo landing sites is truly a fascinating subject."

Amen to that statement Glint.

I once tried to put together an Excel Spreadsheet of the landing site candidates by mission and time from the various tables in Where No Man Has Gone Before and the info in To A Rocky Moon, but soon determined that a two-dimensional sheet was too restrictive. And this spreadsheet did not even include the newly discovered tables included in The International Altas of Lunar Exploration!

Sadly, some of the people involved in the creation of these lists and those who made the final choices are passing into history. And who know how many preliminary or rough draft landing site tables ended up in some dumpster.

Delta7

At one point Apollo 14 was targeted for Censorinus Crater and Apollo 15 (last H-Series Mission) was targeted for Littrow. (Following a successful Apollo 13 landing at Fra Mauro).

mach3valkyrie

quote:Originally posted by Headshot:That is an interesting list. Did the publication indicate who or what committee generated it?

Not specifically. This list was at the end of an article about 'Astronauts' in encyclopedia format. The contributor's name was given. In part it said, "After the successful Apollo 11 mission, NASA announced a schedule of nine more lunar landing missions, Apollo 12 through Apollo 20."

ilbasso

I remember very vividly as a teenager keeping up with all the possible landing sites. I plotted them on the Moon map on my wall, and I kept a running list of them. They all seemed highly exotic at the time!

I cut down and sawed up a tree in our back yard to earn the money to buy a copy of "The Moon as Viewed By Lunar Orbiter" from the Government Printing Office in 1970. The book came with some red-blue glasses and included really incredible 3D views of Tycho and Schroeter's Valley. While Hadley became a nice substitute for Schroeter's Valley, I was bitterly disappointed that we never had the chance to visit Tycho or Copernicus.

Headshot

Returning to the Schroter's Valley issue for an instant, albeit slightly off-topic.

During the Block III portion of the Ranger Program. Schroter's Valley made the final cut for the Ranger IX's impact site list, part of which is as follows:

I have found a reference that indicates IX would have been aimed at the Cobra's Head.

SaturnV

quote:Originally posted by Glint:Here's a a 1968 report...

This makes an interesting read. Wow! What an ambitious mission. Even if we had landed at Marius Hills, I can't believe even a fraction of the suggested experiments could be accomplished.

Note that on page 20 they allocated only five minutes for an astronaut to select a location and then place a heat flow probe! Isn't this the experiment that caused so much time delay on Apollo 15?

I enjoy looking at the Apollo landing sites with my telescope, thanks to the link I'll check out the Marius Hills site at the next opportunity.

carmelo

What if the service module of Apollo 13 not had any problem, and Lovell and Haise were dropped happily on the moon and safely come back on the Earth? If Apollo 13 was a complete success how would change the Apollo program?

For example, Apollo 15 would be a J mission? And we would have had at least Apollo 18?

Editor's note: Threads merged.

Fra Mauro

That's hard to say. A successful Apollo 13 probably would not have changed the view of space exploration by Nixon or the Congress, so the budget cuts are likely to have remained.

The near-disaster of 13 is said to have made NASA management more gun-shy about the program. If Apollo 13 was a success, perhaps NASA would have fought the cuts. That would determine if Apollos 18 and 19 remained. My humble guess is that 19 would have been cancelled in any scenario, 18 flies, 15 flies with the rover.

Headshot

Slightly off topic, it is interesting to note that had Apollo 13 completed its mission without incident and Apollo 15 and Apollo 19 not been cancelled, NASA would have probably adhered to its original launch schedule, albeit shifted by one month due to 13 flying in April 1970, not March, as originally planned.

That one month shift, cascading down the mission line might have caused Apollo 19 to fly in Aug 1972, when one of the most intense solar flares on record occurred.Considering our understanding of the medical implications of such an exposure and the treatments then available, the crew would have most likely been able to return to earth, where they would have succumbed to the their exposure.

carmelo

This is interesting.

schnappsicle

quote:Originally posted by SaturnV:...they allocated only five minutes for an astronaut to select a location and then place a heat flow probe! Isn't this the experiment that caused so much time delay on Apollo 15?

The problem Scott had drilling the holes for the heat probe were caused by a faulty drill bit design that would not allow the lunar soil to be removed from the hole as the drill went down. While he was drilling a hole, he was compacting the soil around the hole, which made it nearly impossible for him to remove the drill once he reached the desired depth. The drill bits were redesigned and the problem was corrected in time for the Apollo 16 mission.

Either way, your point is well taken. There's no way anyone could have drilled a hole in the 5 minutes allotted, even with a fully functioning drill.